


Celestial

by ReaWrite



Series: Stargazing [1]
Category: Undertale (Video Game)
Genre: F/M, Female Reader, Minor Injuries, Reader Is Not Frisk, Reluctant Sadist, Sadistic Thoughts, Third Person POV
Language: English
Status: Completed
Published: 2016-02-03
Updated: 2016-02-03
Packaged: 2018-05-18 02:30:38
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 966
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5894611
Author URL: https://archiveofourown.org/users/ReaWrite/pseuds/ReaWrite
Summary: <blockquote class="userstuff">
              <p>He’s thinking about getting into the telescoping business.</p>
            </blockquote>





	Celestial

With all the grace of a newborn foal, Sans stumbles into his room swearing underneath his breath, slamming the door shut by throwing himself back-first into it before sliding down the wooden barrier, his face twisted into an all-encompassing grimace. Not for the first time that day, he tempts himself with the thought of burying his fucked-up head in the ground and staying there for the rest of eternity.

Sweat rolls down his neck as the memories of the last hour replay over and over again in his mind. Grilby’s. Her. Fries. Ketchup. Her. Spill. _Her_ –

He doesn’t know when it had all started. Maybe it was when she got a bruise knocking her thigh against the coffee table some weeks back. Monster food heals the soul, not flesh, and so Sans is there to witness first-hand how differently humans recover from being injured. The blood under her skin wells into an angry red splash of watercolor on canvas, slowly shifting into dark purple as the days go by and it heals. She wears shorts often, and everytime he catches a glimpse of the bruise, he is oddly reminded of a nebula.

When it finally disappears, he notices other parts of her skin. The way it bends and stretches over muscle. Her freckles, blemishing her arms and cheeks and nose, makes him think of stars, and he secretly draws and names her own constellations. Her stretch marks are the Milky Way. Her scars, comets.

When Sans passes her his joke book one day and she gets a paper cut flipping through the pages, he finds his eyes inexplicably drawn to the small dot of blood blooming on her finger just before she pops it in her mouth to lick it clean, wincing. He swallows with a throat that doesn’t exist.

And when it heals within one day without leaving a trace behind, Sans is unnerved at the strange feeling of near _disappointment_ that hides somewhere in the cavity of his chest. From there, it’s like the dam holding himself together breaks, releasing flood after flood of disturbing thoughts that constantly render him taken aback.

He wants to find every star on her body. He wants to see her skin painted with more beautiful nebulae. No, he realizes. He wants to paint them _himself_. He wants to birth shooting stars across her back, slice the rings of Saturn against her veins, puncture wayward asteroids into her neck.

And now, god, he wants to sink his teeth into her so badly it almost terrifies him. He wants to feel the pulsar of her heartbeat flutter between his canines. Hear the angelic sounds she makes, wondering if maybe Heaven really does exist somewhere out there.

Her body is a universe. And he, Sans thinks wryly to himself, must be a black hole.

He certainly wants to crush her like one.

Despite everything, he manages to maintain a friendly relationship with the human. They exchange jokes, cook with Papyrus, watch the MTT channel, go on about life like he isn’t some sick fuck daydreaming about hurting someone he’s genuinely come to care for over the months.

At least, until today, which is precisely when it all goes to shit.

It’s Wednesday, which is half-off fries day at Grillby’s so he and the human stop by for a casual snack. They order their usual, two fries, with the ketchup bottle privileges going to Sans while Grillby hands the human some ketchup packets. The first time she saw him sip out of it like a drink, her face twisted in disgust, and always requested for individual condiment packets ever since.

Turned out to be his undoing. She squeezes too hard when ripping the corner, squeaking in surprise when a stream of ketchup suddenly splatters the length of her arm all the way up to her shoulder. She doesn’t notice the look on Sans’ face as she groans over ruining her shirt, reaching for a napkin. She dabs at her shoulder first, slowly making her way down, and his small white irises follow the trail intently before shutting completely off and leaving his eye sockets black.

Just as she makes it to her elbow, Sans reaches out and snatches her by the wrist. His magic thrums in his body, collecting inside his jaw as she releases a noise in confusion and he leans down. He feels her seize up as he then proceeds to _lick_ the ketchup from her wrist, pretending it’s something else.

When he remembers himself he pulls back like he touched something burning. And he then gets caught in the way her face is aflame with a blush, blooming a brilliant red color that only continues to deepen with each passing second and in that moment he can only think of one word in his mind–

 _Supernova_.

Sans finally pulls himself together after that, adopting the ever familiar emotional mask he’s practiced for years as he relaxes into a lazy expression, waving it off and hoping she doesn’t pick up on how damn sweaty the back of his skull is.

“didn’t, uh, wanna waste any ketchup,” he says, winking.

She seems to buy that, thank god, but only after several uneasy moments of gathering her bearings while cradling her wrist to her chest. She nods, and laughs shakily.

The rest of their meal is carried with a stiff awkwardness, and once Sans makes it back home he immediately retreats into his room, where he is now slumped against the door and burrowing into his hoodie.

As if he doesn’t hate himself enough already, replaying the events in his mind only serves to elicit another magical response that is now pushing against the front of his shorts.

Groaning, Sans drags his hands down the front of his face.

“i’m so fucked.”


End file.
